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2021-12-23firmware: Move memcpy/memset mapping to fw_base.SAnup Patel
Some of the external firmwares using OpenSBI as library are facing issues with the weak memcpy() and memset() aliases in libsbi.a so we move these to fw_base.S. This way mapping of implicit memcpy() or memset() calls to sbi_memcpy() or sbi_memset() will only be done for OpenSBI firmwares. (Refer, https://github.com/riscv-software-src/opensbi/issues/234) In addition, we also add memmove() and memcmp() mappings in fw_base.S because as-per the GCC documentation the freestanding environment must provide memcpy(), memmove(), memset(), and memcmp(). Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>
2021-12-22lib: sbi: simplify pmp_set(), pmp_get()Heinrich Schuchardt
pmpcfg_csr and pmpcfg_shift are only negative for an unexpected value of __riscv_xlen. We can immediately return in this case. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-12-11lib: sbi: Fix compile errors using -Os optionAnup Patel
When compiling with -Os option along with -ffreestanding, both GCC and clang will add implicit calls to memcpy() and memset() for stack variables initialized in declaration. The C standard as per Clause 4, the compiler cannot necessarily assume that anything beyond: * float.h * iso646.h * limits.h * stdalign.h * stdarg.h * stdbool.h * stddef.h * stdint.h * stdnoreturn.h * fenv.h * math.h * and the numeric conversion functions of stdlib.h. This patch maps memcpy() and memset() as weak-alias of sbi_memcpy() and sbi_memset() respectively so that implicit calls to memcpy() and memset() will compile properly. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Xiang W <wxjstz@126.com>
2021-12-11lib: pmu: check SSCOF before maskingNikita Shubin
We should check if SSCOF extension is present, before applying inhibit mask and clearing overflow, otherwise undesirable value can be written in MHPMEVENT_N CSR. Signed-off-by: Nikita Shubin <n.shubin@yadro.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com>
2021-12-03lib: pmu: support the event ID encoded by a bitmap.Vincent Chen
RISC-V privilege specification does not specify how to encode the event ID. Therefore, each platform is allowed to customize its own encoding rule. The common encoding methods are as follow, directly assigning a number to an event, or every bit in the mphmevent CSR controls one specified event or mixes the above two methods. To enable OpenSBI to support the above three encoding methods simultaneously, this patch repurpose the dt property "riscv,raw-event-to-mhpmcounters". The "riscv,raw-event-to-mhpmcounters" will describes the one or multiple raw events that could be counted by a set of counters. But, the column number of "riscv,raw-event-to-mhpmcounters" is extended from 2 to 3. The 1st column (64bit) is the ID of the raw events. The 2nd column (64bit) represents a select_mask now to represent the bits used for event ID encoding. If a platform directly encodes each raw PMU event as a unique ID, the value of select_mask will be 0xffffffff_ffffffff. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Atish Patra<atishp@rivosinc.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-12-02lib: sbi: Improve fatal error handlingJessica Clarke
BUG and BUG_ON are not informative and are rather lazy interfaces, only telling the user that something went wrong in a given function, but not what, requiring the user to find the sources corresponding to their firmware (which may not be available) and figure out how that BUG(_ON) was hit. Even SBI_ASSERT in its current form, which does include the condition that triggered it in the output, isn't necessarily very informative. In some cases, the error may be fixable by the user, but they need to know the problem in order to have any hope of fixing it. It's also a nuisance for developers, whose development trees may have changed significantly since the release in question being used, and so line numbers can make it harder for them to understand which error case a user has hit. This patch introduces a new sbi_panic function which is printf-like, allowing detailed error messages to be printed to the console. BUG and BUG_ON are removed, since the former is just a worse form of sbi_panic and the latter is a worse version of SBI_ASSERT. Finally, SBI_ASSERT is augmented to take a set of arguments to pass to sbi_panic on failure, used like so (sbi_boot_print_hart's current error case, which currently manually calls sbi_printf and sbi_hart_hang): SBI_ASSERT(xlen >= 1, ("Error %d getting MISA XLEN\n", xlen)); The existing users of BUG are replaced with calls to sbi_panic along with informative error messages. BUG_ON and SBI_ASSERT were unused (and, in the case of SBI_ASSERT, remain unused). Many existing users of sbi_hart_hang should be converted to use either sbi_panic or SBI_ASSERT after this commit. Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>
2021-11-30lib: sbi: Resolve the uninitialized complaint in sbi_pmuDong Du
A recent commit (b28f0700) turns to read from CSR_MCOUNTINHIBIT after checking the SBI_HART_HAS_MCOUNTINHIBIT HART feature, which leaves the mctr_inhbt uninitialized in pmu_ctr_find_hw(). As a result, compiler will complain: error: 'mctr_inhbt' may be used uninitialized in this function. This commit resolves the issue by assigning an initial value to mctr_inhbt. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-11-30lib: sbi: Fix missing spaceNikita Shubin
Fix missing space in sbi_hart_pmp_configure error printing. Signed-off-by: Nikita Shubin <n.shubin@yadro.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Xiang w <wxjstz@126.com>
2021-11-23lib: sbi: Fix spelling of "address" in sbi_domain.cVagrant Cascadian
Fix a spelling typo in error print. Signed-off-by: Vagrant Cascadian <vagrant@debian.org> Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com>
2021-11-12lib: sbi: clear pmpcfg.A before setting in pmp_set()Xiang W
We should clear A bits in prot variable before enabling A_NA4 or A_NAPOT. Signed-off-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-11-11lib: sbi: Fix PMP address bits detectionVasan VS
We should ensure that pmpcfg0.pmp0cfg is set to zero before using pmpaddr0 CSR for detecting implemented PMP address bits. Fixes: bf21632860b4 ("lib: sbi: Detect PMP granularity and number of address bits") Signed-off-by: Vasan VS <vasan.vs@gmail.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
2021-11-11lib: sbi: Fix initial value mask while updating the countersAtish Patra
The first 32 bits of the initial value for the counter should be preserved while updating the mhpmcounter for 32bit. Fixes: 13d40f21d588e ("lib: sbi: Add PMU support") Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-11-11lib: sbi: Enable PMU extension for platforms without mcountinhibitAtish Patra
Some platforms such as hifive unmatched doesn't implement mcountinhibit csr. However, it has hardware events that can be monitored using 2 hpmcounter it has (i.e. mhpmcounter3 & mhpmcounter4). Currently, PMU extension disabled if mcountinhibit is absent. That's not really necessary as long as the supervisor OS keeps track of the delta value of the counters. Without mcountinhibit, the delta value won't be entirely accurate because the counters are freely running. However, that should be fine to produce an approximate counter value which can help performance analysis. Perf sampling won't work though as sscof extension is not present in hifive unmatched. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Counter info width should be zero indexedAtish Patra
The mhpm bits represent the number of bits available in mhpmcounter while counter width describes a zero indexed value. Fix the counter width calculation. Fixes: 13d40f21d588 ("lib: sbi: Add PMU support") Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Reset the mhpmevent value upon counter resetAtish Patra
The hardware solely relies on the event selector value in mhpmevent to figure out what event to monitor using that counter. It should be reset when counter reset happens. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Allow programmable counters to monitor cycle/instret eventsAtish Patra
A platform may use programmable counters for cycle/instret events. The priv spec allows that provided that cycle/instret also report those events in addition to the programmable counters. We should allow that functionality in OpenSBI. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Always enable access for all countersAtish Patra
OpenSBI doesn't use any counters for its own usage. Thus, all the counters can be made accessible for lower privilege mode always. However, the mcountinhibit must be set so that the counter doesn't increment. As a result, we don't have to enable/disable mcounteren at every start/stop. Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Support sscofpmf extension in OpenSBIAtish Patra
This patch adds sscofpmf extension in pmu module which includes following things. 1. Enable overflow irq when starting a counter. 2. Setting the correct event filters passed from supervisor. 3. Delegating the overflow interrupt to the supervisor. 4. Add RV32 support for sscofpmf. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Delegate PMU counter overflow interrupt to S modeAtish Patra
OpenSBI doesn't handle PMU counters for now. Delegate the overflow counter to S-mode always. Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Detect Sscofpmf extension at run timeAtish Patra
Sscofpmf ISA extension introduces PMU counter overflow and filtering support. It introduces a read only `scountovf` csr that can be used to detect if a hart supports this extension at runtime. However, this feature is only useful if the hart already supports mcounteren and mcountinhibit. Add a dynamic detection mechanism and boot time print message if sscofpmf is present. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11lib: sbi: Update csr_read/write_num for PMUAtish Patra
The Sscofpmf extension introduces mhpmevent[h] csrs to handle filtering /overflow bits in RV32. There is no way to read/write mcountinhibit using mcountinhibit csr using a variable. Updated the support to read/write mhpmevent[h] and mcountinhibit csr. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-08lib: sbi: move sbi_boot_print_general()Heinrich Schuchardt
Moving the sbi_boot_print_general() call after the sbi_platform_final_init() call allows to print devices initialized in the latter. To keep the overall print sequence the same also move sbi_boot_print_domains(). Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-11-02lib: sbi: Fix GPA passed to __sbi_hfence_gvma_xyz() functionsAnup Patel
The parameter passed to HFENCE.GVMA instruction in rs1 register is guest physical address right shifted by 2 (i.e. divided by 4). Unfortunately, we overlooked the semantics of rs1 registers for HFENCE.GVMA instruction and never right shifted guest physical address by 2. This issue did not manifest for hypervisors till now because all H-extension implementations (such as QEMU, Spike, Rocket Core FPGA, etc) we tried till now were conservatively flushing everything upon any HFENCE.GVMA instruction. This patch fixes GPA passed to __sbi_hfence_gvma_vmid_gpa() and __sbi_hfence_gvma_gpa() functions. Fixes: 331ff6a162c1 ("lib: Support stage1 and stage2 tlb flushing") Reported-by: Ian Huang <ihuang@ventanamicro.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
2021-11-02lib: sbi: Refine addr format in sbi_printfDong Du
Although we have PRILX to help us print unsigned long without considering the 32bit/64bit differences, there are still some places using 08lx and 016lx manually --- leading to redundant code. This commit fixes the issue by using PRILX all the time. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-10-20Makefile: Add build time and compiler info stringWei Fu
When we are doing opensbi development, we want to know the build time and compiler info for debug purpose. To enable this message, please add "BUILD_INFO=y", like: ``` make BUILD_INFO=y ``` NOTE: Using `BUILD_INFO=y` without specifying SOURCE_DATE_EPOCH will violate "reproducible builds". So it's ONLY for development and debug purpose, and should NOT be used in a product which follows "reproducible builds". Signed-off-by: Wei Fu <wefu@redhat.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2021-10-18lib: sbi: system reset with invalid parametersHeinrich Schuchardt
The SBI specification requires that sbi_system_reset() returns SBI_ERR_INVALID_PARAM if reset_type or reset_reason are not valid. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com>
2021-10-18lib: sbi: Save context for all non-retentive suspend typesAnup Patel
Instead of saving context only for default non-retentive suspend, we should save context for all non-retentive suspend types. Fixes: 74756891cc35 ("lib: sbi: Implement SBI HSM suspend function") Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Xiang W <wxjstz@126.com>
2021-10-11lib: sbi: add priority for reset handlerNikita Shubin
Let's make system_reset_check returning priority instead of only true/false. In that case 0 - means not supported, and anything above means priority that makes existing reset handlers being used in first place, unless it is decided to lower their priority. The handler with the most priority wins. Signed-off-by: Nikita Shubin <n.shubin@yadro.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-10-11lib: sbi: convert reset to listNikita Shubin
To support different handlers for different types of resets, we are adding a sbi_list of restart handlers. Instead of sbi_system_reset_set_device we use sbi_system_reset_add_device to reflect the actual meaning. Signed-off-by: Nikita Shubin <n.shubin@yadro.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-09-26lib: sbi: Add generic timer delay loop functionAnup Patel
We now have frequency of the timer device provided by the platform support so we can emulate desired delay using a loop where the number loop iterations are based on timer frequency. This patch provides sbi_timer_delay_loop() for above purpose. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Xiang W <wxjstz@126.com>
2021-09-26lib: sbi: Print timer frequency at boot timeAnup Patel
We now have frequency in timer device instance provided by platform so let's print timer frequency as part of the boot prints. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Xiang W <wxjstz@126.com>
2021-09-22lib: sbi: Add BUG() macro for csr_read/write_num() and misa_string()Xiang W
We use BUG() macro in csr_read_num(), csr_write_num(), and misa_string() functions for unhandled cases. Signed-off-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-09-22lib: sbi: fix ctz bugXiang W
The original version of ctz will cause an endless loop, if the parameter passed in is 0. This commit fixes this bug. Signed-off-by: Xiang W <wxjstz@126.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-09-03lib: sbi: Refine the way to construct platform featuresDong Du
sbi_platform_get_features_str() uses sbi_snprintf() to construct the features_str. However, it passes the wrong length value (i.e., the nfstr), which should be (nfstr-offset) as the starting point of str (i.e., features_str + offset) changes. This commit also checks the return value of snprintf, and handles the corner case that the string buffer is full. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-09-03lib: sbi: Checking fifo validness in sbi_fifo_is_empty and is_fullDong Du
As other exported fifo functions, we should check whether the fifo is valid in sbi_fifo_is_empty and sbi_fifo_is_full. To this end, this patch changes the retval from bool to int, and the two functions will return SBI_EINVAL in the case the fifo is invalid. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-08-30lib: sbi: protect dprintf output with spinlockDong Du
Avoid getting messages from multiple harts (using dprintf and printf) concurrently with a spinlock serializaing calls to sbi_dprintf(), sbi_printf() and sbi_puts() Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-08-30lib: sbi: Correct typo in faults delegation CSR nameRahul Pathak
Correcting the name of faults delegation CSR %s/mfdeleg/medeleg Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-08-20lib: sbi_trap: Restore redirect for access faultsSamuel Holland
commit 764a17d852a8 ("lib: sbi: Implement firmware counters") added switch cases for CAUSE_LOAD_ACCESS and CAUSE_STORE_ACCESS. This caused them to stop being redirected to U or S mode, as that is handled in the default switch case. As a result, an error in userspace could cause the system to hang. Fix this by allowing the acces fault case to fall through to the default case. Fixes: 764a17d852a8 ("lib: sbi: Implement firmware counters") Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-08-20lib: sbi: Fix bug in sbi_ecall_rfence that misses checkingDong Du
In sbi_ecall_rfence_handler, it will compare the funcid with REMOTE_HFENCE_GVMA and REMOTE_HFENCE_VVMA_ASID. Later it check whether the misa includes H-extension. This checking is incomplete which misses REMOTE_HFENCE_GVMA_VMID and REMOTE_HFENCE_VVMA. Fix the issue by updating the checking range. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-08-07lib: sbi: Fix bug in strncmp function when count is 0Dong Du
No need to compare characters when the count turns to 0. Fix the issue in sbi_strncmp. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-07-11lib: sbi: Fix sbi_pmu_exit() for systems not having MCOUNTINHIBIT csrAnup Patel
The sbi_pmu_exit() crashes on systems not having MCOUNTINHIBIT csr so to fix this we check SBI_HART_HAS_MCOUNTINHIBIT feature in sbi_pmu_exit() and do nothing if it is not available. Fixes: 13d40f21d588 ("lib: sbi: Add PMU support") Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-07-11lib: sbi: Improve TLB function namingAtish Patra
Follow the standard conventon for static function names: All global functions should be start with sbi_<module name>_ All static functions should be start with <module name>_ Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Implement firmware countersAtish Patra
RISC-V SBI v0.3 specification defines a set of firmware events that can provide additional information about the current firmware context. All of the firmware event monitoring are enabled now. The firmware events must be defined as raw perf event with MSB set as specified in the specification. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Implement SBI PMU extensionAtish Patra
RISC-V SBI specfication 0.3 defines a PMU extension that allows supervisor mode to start/stop/configure pmu related events. This patch implements all of the functionality defined in the specification. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Add PMU supportAtish Patra
RISC-V SBI v0.3 specification defined a PMU extension to configure/start/stop the hardware/firmware pmu events. Implement PMU support in OpenSBI library. The implementation is agnostic of event to counter mapping & mhpmevent value configuration. That means, it expects platform hooks will be used to set up the mapping and provide the mhpmevent value at runtime. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Use csr_read/write_num to read/update PMU countersAtish Patra
Currently, csr_read/write_num functions are used to read/write PMP related CSRs where CSR value is decided at runtime. Expand this function to include PMU related CSRs as well. Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Remove redundant boot time print statementAtish Patra
This patch removes redundant print from sbi_boot_print_hart(). Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Disable m/scounteren & enable mcountinhibitAtish Patra
Currently, all bits in mcountern are enabled unconditionally at boot time. With SBI PMU extension, all the programmable counters should enabled only during performance monitoring for a particular event. However, this is done only if mcountinhibit is implemented because the supervisor mode can not start/stop any event without mcountinhibit. Similarly, supervisor should take care enabling scounteren which allows U-mode to access programmable pmu counters. All the non-programmable ones (CY, TM, IR) should be enabled in M-mode because some userspace may rely on builtins such as __builtin_readcyclecounter. Supervisor OS can still disable them during initial configuration. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Detect number of bits implemented in mhpmcounterAtish Patra
RISC-V privilege specification allows the implementation to have less than 64 bits. Add a function to detect the number of implemented bits in mhpmcounter dynamically at runtime. Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11lib: sbi: Remove stray '\' characterAtish Patra
Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>